Dressage with a scalpel rather than an axe

John is still trying to get some of Duke's nuances through to me, and I can ride it while he says it, but I am still struggling to put it into words and repeat it on my own.
The two "easy" takeaways from today's lesson are that my right leg is sitting too far behind the girth (giving Duke an excuse to use it as a haunches aid, and evade the extra work that goes along with putting that right hind leg up and underneath himself) and my left hand has a death grip on the reins when I am giving aids with my right hand, which kind of defeats what the right hand is doing.  So I have to consciously think about pushing my right leg a little more forward and giving, just a bit, with the left rein.  Duke responded very quickly and easily to the left hand, which helped a lot in rewarding my behavior and seeing how he CAN bend to the right when I'm not holding him locked in place so that he can't.
John added a new exercise today, a 3 loop serpentine but from quarter line to quarter line, and sometimes with 10 meter circles thrown in.  He said at home to do it left/right/left loops first, and once Duke starts to bend and give, then add right/left/right.
We worked on Duke's bend, mostly, with the same need to "break up" his reluctance to bend by putting his haunches in, then bending his neck in, then asking him to go forward once he accomplished both.  Sometimes, this also needed just a bit of leg yield out on the circle.
We also worked a little bit on leg yields down the long side, and making sure to use the outside rein.  Duke is easy to feel when he crosses underneath, vs just bending his neck and moving sideways (not that I can always get him to cross, just that I can feel the difference between the two). We also worked on rhythm, and using the half halt to steady him a bit, at both the trot and canter.
At the canter, I need to sit down more, I am letting myself tip forward, and when I use my core to stay planted in the saddle, Duke responds by kind of lifting up into his back.  But it takes a lot of core to stay there, instead of going into a half seat.
This doesn't do the lesson justice describing it, but it was like we'd be riding around, and then I'd feel Duke balance or step under himself, and then there was that "lift", that makes him smoother and easier to ride.  We'd usually only keep it for a few steps, but it was definitely there, and we can definitely do it, but I still need John helping me with the different steps.
We also worked on crossing the diagonal, and keeping Duke steady.  All of this work, was, by the way, far better than anything we did at shows, so that's good too, because after I work with John all winter, I'll hopefully be at this level at a show by next year, which will be a big improvement.
After the lesson, there were some geese walking in the show jumping arena.  Duke's eyes got huge and I could feel his little heart beating under my leg.  They were just walking around and quacking, but Duke was blown away.  I guess they do sound a little like dinosaurs.
John said that whether he gives a horse a vacation depends on the horse, and so far, Duke seems like the type who probably doesn't need or want one.  I don't want to wear out his legs, but he seems to get crabby when he's not ridden.  He's been a little crabbier in the stall too - I'm guessing all the switching of staff at the barn might be affecting him.  Although of course, it's probably me, oblivious to something I'm doing.